The invention relates to a device for feeding the front end of a wire coil to a drawing installation, having a base, on which a holder is rotatably mounted, and an arm, which is connected to the holder and at its end has a gripper element for taking hold of the front end of the wire coil.
A device of this type which is known from DD 41 927 has a holder on which a radially displacable arm is arranged, the height of which arm can be varied by means of a lifting cylinder. At its free end, the arm bears a gripper element. To take hold of the front end of a coil, the gripper element is moved into the desired position through rotation and lifting or lowering of the arm. Then, the front end of the wire, through pivoting of the arm, is fed via straightening rollers to a clamping vise which provides preliminary guidance for the material in the working direction. This is followed by the wire-drawing operation itself.
A device of this nature requires considerable amounts of space in order to allow the rotary movements required to take place. Furthermore, the gripper elements have to clamp the front end of the wire, and devices for straightening the wire additionally have to be provided in the installation.
The object of the present invention is therefore to provide a device of the type described in the introduction which considerably reduces both the amount of space required and the outlay on equipment compared to this prior art.
To achieve this object, according to the invention in a device of the type described in the introduction, the arm is formed from a base section and an end section,
one end of the base section is connected to the holder, which is mounted rotatably on the base, in such a manner that the base section can pivot about a first pivot axis, the pivot axis of the base section running transversely with respect to the axis of rotation of the holder,
one end of the end section is connected to the other end of the base section, in such a manner that it can pivot about a second pivot axis,
the first and second pivot axes run parallel to one another,
the end section of the arm, at its free end, bears a head unit which is mounted in such a manner that it can rotate about two axes running at right angles to one another and on which a hook-shaped gripper element and a clamping device which straightens the front end of the wire coil are arranged, and
control units are provided for pivoting or rotating the holder, the arm sections and the head unit.
The fact that according to the invention the arm is divided into two sections mean that the space required is considerably reduced both in the working position and in the standby position. In addition, the clamping device in this case at the same time fulfills a straightening function. Consequently, compared to the prior art it is possible to dispense with a clamping device which is used only to feed the front end of the wire to a straightening unit. The device is particularly suitable for wire diameters of 10 mm and above.
The front end of the wire is introduced into a drawing machine by means of the device, but may also be fed to a pointing unit connected upstream of this machine.
Furthermore, according to the invention the gripper element is mounted on the head unit so as to be able to pivot in a controlled manner. In this way, it is possible to take hold of the wire element and introduce it into the clamping device.
Furthermore, according to the invention the control units are hydraulic or pneumatic units.
Furthermore, according to the invention the clamping device is formed from two rows of pressure-exerting rollers which guide the wire between them and prestraighten it.
Furthermore, according to the invention the rows of pressure-exerting rollers are mounted in such a way that they can be adjusted relative to one another.
Furthermore, according to the invention individual pressure-exerting rollers in one row are mounted in such a manner that they can be adjusted relative to pressure-exerting rollers in the other row.
Furthermore, according to the invention at least two pressure-exerting rollers which are arranged opposite one another are connected to a rotary drive.
Finally, according to the invention the direction of rotation of the rotary drive can be reversed. This makes it possible to operate two lines of wire-drawing machines with only one device according to the invention, in which case the device interacts with two coils which are each resting on a spool. In this case, the device is expediently positioned between the two lines.